Part I: Changes in Food and Drink

We don’t live the way our ancestors did.

How we eat and drink, how we sleep, how we exercise, how we clean, and even how we’re born is very different today than it has been throughout human history. Many developments of contemporary life have benefited our health, like water sanitation and modern medicine. But there are plenty of recent developments that have harmed us. And a big part of why they’re not good for our health is because they’re not good for our guts.

In this series of articles, we’ll consider common habits of contemporary life that endanger our gut architecture, starting with what we eat and drink.

How We Eat

Human beings have been walking this planet for roughly 2.5 million years. For most of that time, we subsisted mainly on minimally processed plants. It was only with the advent of the Neolithic Age (about 12,000 years ago) and the Industrial Revolution (about 200 years ago) that our diet changed drastically, first with the introduction of agriculture and animal husbandry, and next with the introduction of refined foods.

To put these changes into perspective, we’ve only been planting crops and raising animals for 0.004% of our time on earth, and we’ve only been eating a modern Western diet for 0.0001% of our existence. Those are pretty radical dietary shifts for the human body to adjust to in such a small amount of time. And judging by the ubiquity of chronic conditions plaguing industrialized society, it appears our bodies haven’t adjusted very well. One striking example is the condition of our guts.

Our Diet and Our Microbiome

For a healthy gut, you need a healthy microbiome (the collective DNA of the microbes living inside you). And for a healthy microbiome, you need two things: good microbial diversity (i.e. lots of different bacterial strains) and good gut architecture (i.e. healthy gut anatomy).

Research has shown that people who eat a hunter-gatherer diet, full of fiber-rich whole grains and tubers, have up to 50 percent more gut microbial diversity than folks who consume a modern Western diet.¹ This kind of ancestral diet also supports healthy gut architecture, which is characterized by a nice, tight gut barrier. That’s important, because your gut barrier protects you from the germs and toxins in your food and environment.

Just consider what these food villains are doing to your gut:

Fats:

Saturated fats and trans fats both change the composition of gut bacteria, upsetting the balance between beneficial and harmful strains. ^2,3,4 High-fat diets are also linked to chronic inflammation, which harms your gut architecture. ^5,6

Refined Carbohydrates:

Refined carbs, such as white bread, pasta, and rice, are low in fiber. That’s a problem, because fiber is your gut bacteria’s very favorite food. If you’re filling up on processed foods, you’re starving these helpful critters. When that happens, they either die off or start feeding on the protective mucus layer of your gut barrier, leading to inflammation. ⁷

Sugar:

Every time you drink a soda, eat a dessert, or even down a glass of orange juice, your system is getting a big jolt of sugar. Unlike fiber, which encourages the proliferation of beneficial gut bacteria, sugar appears to keep these good guys from multiplying. ⁸ Sugar is also harmful to your gut architecture. In fact, a mouse study found that a high-sugar diet exacerbates inflammation of the GI tract. ⁹

Artificial Sweeteners:

Unfortunately, artificial sweeteners may be even worse for you than real sugar. There’s evidence they may reduce beneficial gut bacteria populations by up to 67%! ¹⁰ Ironically, they may also upset the balance of microbes in your gut in ways that make it harder to keep your blood sugar under control. ^11,12,13

So, which foods are good for your gut?

Prebiotic Fiber:

The first step in gut-friendly eating is to fill your beneficial bacteria’s pantry shelves with their favorite snacks. Your gut bacteria are fond of the polyphenols found in plant foods like fruits and vegetables. But what they like best are foods high in prebiotic fiber, such as bananas, beans, lentils, oats, barley, onions, leeks, garlic, apples, and asparagus.[14]

Once your gut bacteria have chowed down on prebiotic fiber, they get busy building your gut architecture — specifically, the protective mucus layer of your gut barrier. And that helps keep inflammation at a healthy level throughout your body.[15]

Fermented Foods:

You can also introduce new beneficial bacteria (or probiotics) to your gut by eating fermented foods. Kefir, yogurt, and kimchi are among the most concentrated sources of friendly flora, but sauerkraut, kombucha, and miso contain some, too.[16]

Just remember — if your gut architecture isn’t healthy, any probiotics you introduce to your system probably won’t stick around. So just eating fermented foods or taking probiotics on its own typically isn’t enough to turn your gut health around.

Plant Protein:

Animal and test tube studies have shown that eating protein from peas and mung beans can improve the ratio of beneficial to harmful bacteria in the gut.[17,18] If that effect holds true for plant protein in general, eating more tofu, tempeh, lentils, and chickpeas is a smart move.

Bonus: beans and pulses contain fiber, so they also support your gut architecture by ensuring good bacteria eat their favorite food instead of your gut mucus layer.

Omega-3s:

Fats aren’t all bad for your gut. In addition to being good for your heart, your brain, and your eyes, the omega-3 fats found in fatty fish, flaxseed, and walnuts also appear to be good for your gut bacteria.[19]

Mouse studies have shown that mice eating a fish oil-enriched diet have higher levels of good bacteria such as Bifidobacterium and Lactobacillus compared to mice eating lard-derived fats.

How We Drink

Early humans led simple lives, and their primary drink was fresh water. Today, people have almost limitless options when it comes to liquid refreshment — many of which are harmful to our guts.

Take a look at the impact of these drinks on your gut:

Sugary Drinks:

Remember how sugar is bad for your good gut bacteria? Well, soda packs a load of it. It might shock you to find out that a 12-ounce can of cola has 39 grams of sugar — or about 10 teaspoons. That’s the same as a candy bar! Juice is certainly healthier than soda due to the phytonutrients it contains, but it has nearly as much sugar: 23 grams per 8-ounce cup. Sports and energy drinks are all full of the stuff too. Gatorade® contains 34 grams per 20-ounce bottle, and Red Bull® is on par with soda at 37 grams per 12-ounce can.

A recent study found that drinking sugar-sweetened soda is associated with lower bacterial diversity. ²⁰ This is consistent with the finding from animal research mentioned previously that sugar inhibits good bacteria from multiplying.

Chlorinated Water:

If you’ve resolved to drink less booze and more water, there is another consideration: the chlorine in your tap water. Drinking water is treated with chlorine to kill harmful bacteria in the water supply, and that’s a good thing. Clean water has eliminated many deadly diseases like cholera and dysentery in developed countries.

But as knowledge of the importance of gut bacteria to human health has grown, some researchers wonder whether chlorinating water could harm the beneficial bacteria inside us. ²⁷ This question has not been widely studied yet, but preliminary animal studies suggest chlorinated water may disrupt the composition of gut bacteria. ²⁸

Alcohol:

Alcohol is no newcomer to the human diet. We’ve been brewing alcoholic beverages from grain, honey, and fruit for 9,000 years. ²¹ However, prehistoric people weren’t in it just for the pleasure of imbibing. Alcohol and drugs played a sacred role in ancient societies, and their use was highly regulated. ²²

Today, not so much. In fact, 30 percent of American adults consume at least one drink per day, and 10 percent ingest about 10 drinks per day. Yes, you read that right. America has an alcohol problem.

Drinking too much alcohol is hard on your beneficial gut bacteria. One study compared the gut bacteria of 41 alcoholics with those of 10 people who drank very little or no alcohol. Researchers found dysbiosis — the scientific term for microbial imbalance — in more than a quarter of the problem drinkers but none of the teetotalers or light drinkers. ^23,24

There’s one exception, however, and it’s good news if you’re a red wine lover. Another study found that when volunteers drank gin or red wine daily for 20 days, there was a marked difference in the changes to their gut bacteria. Gin drinkers saw their numbers of beneficial bacteria fall, while red wine drinkers witnessed increases in beneficial bacteria and improved microbiota composition. That’s probably because wine is rich in polyphenols, and as you may remember, good bacteria love to eat polyphenols. ²⁵

Excess alcohol also damages your gut architecture. It promotes intestinal inflammation, increasing the permeability of your gut barrier and harming the function of your gut mucosal immune system. ²⁶

So, how should you change your drinking habits to support gut health?

Limit Sugary Drinks:

For optimal gut health, limit your consumption of sugary drinks. The World Health Organization recommends adults and children reduce their daily intake of free sugars to less than 10% of their total energy intake, or about 50 grams (12 teaspoons) per day.[29]

It notes that a further reduction to 5% per day would provide additional health benefits.

Switch to Red Wine:

If you want to drink, go for the alcoholic beverage that may provide a gut boost: red wine. Limit hard alcohol to that special occasion when you want a fancy cocktail on a night out.

Invest in a Water Filter:

Whether chlorinated water disrupts our gut microbiota is still an open question, but so far the evidence points that way. Countertop water filters are inexpensive. Investing in one could provide you with peace of mind.

Key Take-Aways

Common habits of contemporary life endanger our gut architecture, starting with what we eat and drink.
Hunter-gatherer cultures, who eat a lot of fiber, have much more gut microbial diversity than Westernized societies. This kind of diet also promotes healthier gut architecture — the actual anatomy of the gut.
Saturated and trans fats, refined carbohydrates, sugar, and artificial sweeteners reduce beneficial gut bacteria populations, negatively alter the composition of the gut microbiota, and inflame gut architecture.
Gut-friendly foods include prebiotic fiber (found in certain fruits, veggies, grains and beans), fermented foods, plant protein, and omega-3 fatty acids.
Sugary drinks, alcohol, and chlorinated water can lower bacterial diversity, cause dysbiosis, and damage gut architecture.
Limiting sugary drinks and switching to red wine may preserve gut health, and investing in a water filter can eliminate chlorine from your drinking water.

References

Links To Our References

What the Modern Lifestyle is Doing to Your Gut – And How to Fix It